There follows a small selection of publications by Trevor Dutton, some written before founding Dutton Simulation.  These are examples of some of the research studies that have brought benefit to our clients, and show how we have assisted in the development and implementation of forming simulation methods.

"Simulating the Complete Forming Sequence for a Roll Formed Automotive Bumper Beam", T Dutton, P Richardson, M Tomlin*, T Harrisaon*, 6th European LS-DYNA Users' Conference 2007

As part of the development of a new automotive bumper beam, a complete simulation of the entire forming process was carried out using LS-DYNA. The material for the beam was an ultra high strength steel presenting many challenges for the forming process. The sequence of forming operations was roll-forming (including forming a sweep in the initially straight roll-formed section), local annealing, forming of an initiator in the wall of the section and then crushing the end of the previously rolled section. The forming results (geometry, thinning and work hardening) were all transferred to the simulation of the bumper performance under various impact conditions.

The paper describes the development of certain novel simulation techniques, particularly for the roll-forming for which the implicit analysis options of LS-DYNA were used, representation of the annealing process, as well as the method in which data was transferred between the various simulations. Above all, we describe how the simulations were used to guide the design of the bumper beam system up to the point of prototype manufacture and test.

Keywords:
Roll forming simulation, implicit analysis, automotive bumper beam design, Ultra High Strength Steel

* Wagon Automotive

Read the full paper; left mouse on link to open in a new window, right mouse to save to your local drive (697 kB)

"Tool Design for a High Strength Steel Side Impact Beam with Springback Compensation", T Dutton, R Edwards*, A Blowey*, 5th European LS-DYNA Users' Conference 2005

Prediction of formability for sheet metal pressings has advanced to a high state of confidence in recent years. The major challenge is now to predict springback and to assist in the design of tooling to correctly compensate for springback. This is particularly the case for materials now being routinely considered for automotive production, such as aluminium and ultra high strength steels, which are prone to greater degrees of springback than traditional mild steels.

This paper presents a study based on the tool design for an ultra high strength steel side impact beam. The forming and springback simulations, carried out using eta/DYNAFORM (based on the LS-DYNA solver), are reported and compared to measurements from the prototype panels. The analysis parameters used in the simulation are presented, and the sensitivity of the results to variation in physical properties is also reviewed. The process of compensating the tools based on the analysis prediction is described; finally, an automated springback compensation method is also applied and the results compared with the final tool design.

* Wagon Automotive

Read the full paper; left mouse on link to open in a new window, right mouse to save to your local drive (697 kB)

"Review of Sheet Metal Forming Simulation - Progress to Date, Future Developments", T Dutton, LS-DYNA 8th International Conference 2004

Sheet metal forming simulation is a well established application of LS-DYNA. Originally used for trouble shooting, it is now increasingly accepted as a method for testing tooling design prior to manufacture; however, there are further opportunities to apply such methods as early as possible, even in the product design stage. This paper reviews the advances of recent years and presents an example of typical current applications; the tools now offered for die face creation are then discussed. The paper also looks ahead to see how application of these methods might develop and indicates areas for research, in order to achieve the maximum benefit from simulation.

Read the full paper; left mouse on link to open in a new window, right mouse to save to your local drive (790 kB)

"The Effect of Forming on the Crashworthiness of Vehicles with Hydroformed Side Rails", T Dutton, S Iregbu, R Sturt, A Kellicut, B Cowell, K Kavikondala, IBEC 1999

This paper pioneered the extraction of forming results for use in crash analysis.  The effects of forming on the crash performance of hydroformed structures was shown to be dramatic.  The paper demonstrated a viable procedure for transfer of data between models.

This paper was awarded a Best Paper at Conference prize by the SAE.

Read the full paper; left mouse on link to open in a new window, right mouse to save to your local drive (340 kB)

"The Effect of Forming on Automotive Crash Results", Trevor Dutton, Richard Sturt, Paul Richardson, Andrew Knight, IBEC 2001

Following on from the previous paper, this study examined the effect of including thickness changes and work (strain) hardening on stamped panels is examined.  Fourteen panels from a full automotive model were selected for their key role in frontal crash management.  Although the effects were not as dramatic as for the hydroformed rail in the previous work, the effect of forming on crash results was evident.  The paper also examined the best method for the forming simulation, considering the time required against the accuracy of results, and the procedure to streamline the transfer process.

Read the full paper; left mouse on link to open in a new window, right mouse to save to your local drive (1.45 MB)

"Visualisation of Surface Defects in Sheet Metal Panels", T Dutton, E Pask, International LS-DYNA Conference, 1998

The aim of this paper was to take the use of forming simulation beyond the issue of splits and wrinkles to examine the problems of cosmetic defects in automotive skin panels.  The study considered the forming simulation of a roof panel; key to successful prediction of the defect was the springback analysis.  Whilst the simulation clearly identified the defect location and size the real challenge is to visualise that defect in a similar way to that used in quality checking in production.  Ray-tracing methods are explored and a viable approach identified.

Read the full paper; left mouse on link to open in a new window, right mouse to save to your local drive (592 kB)

Other Papers on Sheet Metal Forming Simulation and related topics

“Simulation of Surface Defects in Sheet Metal Panels”, T. Dutton, E. Pask, paper to Simulation of Materials Processing: Theory, Methods and Applications, Huétink & Baaijens (eds), Rotterdam, 1998

“Industrial Application of Forming Simulation: Current Status and Future Developments”, T. Dutton, J. Miles, E. Pask, paper to the 5th International Conference of Sheet Metal, 1997.

“A Demonstration of the Use of Simulation Techniques for the Tooling Industry”, T. Dutton, T. Walton, M. Sheh, J. Walczak, paper to IBEC 95, Detroit MI, November 1995.